Default components / Structure

Heading

Renders ATX headings from H1 through H6, including the optional H1 divider.

HTagblock componentHeadingStyleheadingBuilder

What it renders

Live Flutter preview

Starting the Flutter widget

Rendering this component with gpt_markdown…

This is the real GptMarkdown Flutter widget, rendered with the exact Markdown input shown here.

Markdown input

input.md
1# Release notes 2 3## The important part

Default behavior

Runtime behavior

A hash count from one to six selects the level. The default H1 divider is part of the default heading widget.

Accessibility note

Use heading levels in order so assistive technology can understand the document outline.

Theming & styling

Theme layering guide

HeadingStyle is the component's appearance surface. Set only the values you need; style-sheet values merge field-by-field with the active theme and package defaults.

Style classAvailable fields
HeadingStyletextStyle · padding · showDivider · dividerColor · dividerThickness · dividerPadding
heading_style.dart
1GptMarkdown( 2 markdown, 3 styleSheet: const GptMarkdownStyleSheet( 4 heading: HeadingStyle( 5 textStyle: TextStyle(letterSpacing: -0.4), 6 showDivider: false, 7 padding: EdgeInsets.only(top: 10, bottom: 6), 8 ), 9 ), 10)

App-wide or scoped theme

theme.dart
1GptMarkdownThemeData( 2 brightness: Brightness.light, 3 styleSheet: const GptMarkdownStyleSheet( 4 heading: HeadingStyle( 5 // Set only the values your app needs. 6 ), 7 ), 8)

Builders & callbacks

headingBuilder

Widget Function(BuildContext context, int level, Widget content, HeadingStyle style)

Use this only when the default widget structure is no longer the right shape. The resolved style or configuration is passed where applicable.

Full builder and callback signatures

Safely override the default

A custom component list replaces a default list entirely. Put your matching component first, then append the package defaults so every other Markdown feature continues to render.

keep_defaults.dart
1// Passing components replaces its defaults. Prepend to override matching syntax, 2// then keep every built-in component after it. 3GptMarkdown( 4 markdown, 5 components: [ 6 MyHTagOverride(), 7 ...MarkdownComponent.globalComponents, 8 ], 9)
Custom component guide

Related components